What are the diagnostic criteria for rheumatic heart disease?

Diagnostic Criteria for Rheumatic Heart Disease

The diagnosis of rheumatic heart disease (RHD) requires echocardiographic confirmation using the World Heart Federation (WHF) 2012 criteria, which mandate pathological valve regurgitation combined with specific morphological features, and these criteria must always be interpreted alongside clinical context to exclude other etiologies. 1

Screening Criteria (For Individuals ≤20 Years in High-Prevalence Settings)

A positive screen requires any one of the following echocardiographic findings: 2, 3

• Mitral regurgitation (MR) jet length ≥1.5 cm for patients <30 kg OR ≥2.0 cm for patients ≥30 kg 2, 3
• Any aortic regurgitation (AR) jet observed in at least one view for at least two consecutive frames 2, 3
• Restricted mitral valve leaflet motion with reduced opening 2

Following a positive screen, confirmatory echocardiography by an expert is mandatory before establishing the diagnosis. 3

Confirmatory Echocardiographic Criteria for Definite RHD

The WHF 2012 criteria remain the gold standard and require meeting any one of four subcategories (A, B, C, or D): 1, 2

Subcategory A: Mitral Valve Disease with Regurgitation

• Pathological MR PLUS ≥2 morphological features of RHD of the mitral valve 1, 2
• This is the most common manifestation in young patients 1

Subcategory B: Mitral Stenosis

• Mitral stenosis with mean gradient ≥4 mmHg 1, 2
• Congenital mitral valve anomalies and nonrheumatic mitral annular calcification (in adults) must be excluded 1

Subcategory C: Aortic Valve Disease with Regurgitation

• Pathological AR PLUS ≥2 morphological features of RHD of the aortic valve 1, 2
• Bicuspid aortic valve, dilated aortic root, and hypertension must be excluded 1

Subcategory D: Combined Borderline Disease

• Borderline disease of both aortic AND mitral valves 1, 2
• Combined AR and MR in high-prevalence regions (in absence of congenital heart disease) is highly suggestive of RHD 1

Defining Pathological Regurgitation

Pathological regurgitation requires all four Doppler criteria to be met: 3

• Visible in two views 3
• Jet velocity >3.0 m/s 3
• Pan-systolic (for MR) or pan-diastolic (for AR) jet 3
• Plus morphological features of valve damage 3

Morphological Features of RHD

Mitral Valve Features:

• Anterior mitral valve leaflet (AMVL) thickening 2
• Chordal thickening 2
• Restricted leaflet motion 2
• Excessive leaflet tip motion during systole 2

Aortic Valve Features:

• Irregular or focal thickening 2
• Coaptation defect 2
• Restricted leaflet motion 2
• Prolapse 2

Stage-Based Classification System (2024 Update)

The WHF 2024 guidelines replace the outdated "borderline" and "definite" terminology with a stage-based system (A-D): 2, 3, 4

Stage A (Applies ONLY to age ≤20 years):

• Minimal echocardiographic criteria for RHD met 2, 3
• Pathological MR or AR present without abnormal morphology 2, 3
• Low risk of progression based on risk score 2, 3
• Management: Enrollment in RHD registry; secondary antibiotic prophylaxis (SAP) initiation is reasonable (Class 2A) 3

Stage B: Mild RHD 3

Stage C: Advanced RHD 3

Stage D: Advanced RHD with established complications 3

Technical Requirements for Echocardiographic Assessment

The following modalities are mandatory: 2, 3

• 2D echocardiography for morphological assessment 2, 3
• Continuous-wave Doppler for velocity measurements 2, 3
• Color-Doppler for regurgitation detection 2, 3
• Optimal gain settings without harmonics and with frequency ≥2.0 MHz 2

Critical Clinical Context and Caveats

Age-Related Modifications:

• Criteria are modified for individuals >20 years because valvular features develop over time 2, 3
• Stage A classification applies only to individuals ≤20 years old 2, 3

Clinical Integration:

• Echocardiographic findings must always be interpreted with clinical findings and consideration of pretest probability based on geographical location, ethnicity, and living conditions 1
• In patients with a history of definite acute rheumatic fever (ARF), any structural/functional valve abnormality must be considered RHD until proven otherwise 1

Exclusion of Mimics:

• Congenital anomalies (bicuspid aortic valve, mitral valve cleft) must be excluded 1, 2
• Degenerative changes (rare in young patients) must be excluded 1
• Other acquired conditions (infective endocarditis) can be differentiated by clinical findings 1

Valve Involvement Patterns:

• RHD predominantly affects left-sided valves 1
• Tricuspid/pulmonary valve involvement is rare without mitral valve disease (99.3% have coexisting mitral valve disease) 1
• Isolated aortic stenosis is rare (0-0.5%); therefore, right-sided lesions and isolated aortic stenosis are not included in diagnostic criteria 1

Subclinical Disease:

• RHD detected on echocardiography without a clinically pathological cardiac murmur is termed "subclinical RHD" 2, 3
• Subclinical lesions detected by Doppler can persist long-term and are not necessarily transient 5
• Individuals with subclinical definite RHD should be considered to have RHD (after excluding other etiologies) and secondary prophylaxis should be offered 1

Prophylaxis Timing:

• Although confirmatory echocardiography is recommended before SAP initiation, in settings where immediate confirmatory studies are unavailable, SAP can be initiated while awaiting confirmation 3
• This approach is justified because individuals with mildly clinical definite RHD benefit most from secondary prophylaxis 1

Common Pitfalls to Avoid

• Do not apply screening criteria using handheld echocardiography without understanding the modified criteria (no continuous-wave Doppler available, so velocity measurements cannot be obtained) 1
• Do not diagnose RHD based on isolated morphological features without pathological regurgitation or stenosis 1
• Do not overlook the need for expert confirmation after positive screening in non-expert settings 3
• Do not use these criteria for diagnosing carditis in acute rheumatic fever or in patients with known ARF history 1